JPH07237520A - Gas generator for air bag - Google Patents

Abstract

PURPOSE:To prevent the deformation of the ceiling part of a gas generator, and to improve its outside appearance and to make the attaching of a mechanical sensor possible by composing the housing of the gas generator of the first member consisting of a central cylinder part, an annular part and an outer cylinder part and the second member consisting of an annular part and an inner cylinder part. CONSTITUTION:In a gas generator, an accommodating chamber 15 for ignition means 16, 17 and a combustion chamber 18 to accommodate a gas generating means 20 are partitionedly formed inside a housing 2 having a gas exhaust mouth 1. In this case, the housing 2 is composed of the first and the second member 3, 4 and a cover member 22. The first member 3 is formed of a central cylinder part 5 opened at only one end, an annular part 6 extending flange-shapedly to the above opened end, and an outer cylinder part 7 extending axially on the outer edge of the annular part 6. The second member 4 is formed of an annular part 10 having a central hole 9 in which the central cylinder part 5 is fitted and an inner cylinder part 11 extending axially to the annular part 6 of the first member 3 on the outer edge of the annular part 10. In addition, an accommodating chamber 15 and the combustion chamber 18 are partitionedly formed inside and outside the central cylinder part 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas generator for an air bag for protecting an occupant from an impact, and more particularly to a structure of a housing thereof.

[0002]

2. Description of the Related Art An example of a conventional gas generator is shown in FIG. This gas generator has a gas outlet 40
41 having a housing, and an ignition means arranged in the housing 41, that is, an igniter 49 and a transfer charge 50.
And a canister container 43, which is a thin-walled aluminum container filled with a gas generating agent 47, which is ignited by these. Housing 41
Is a large-diameter inner cylinder member 4 with one end closed and the other end open.
4, a combustion chamber 46 is defined inside the inner cylinder member 44, and a coolant / filter chamber 45 is defined outside the inner cylinder member 44. The canister container 43 is arranged in the combustion chamber 46. The igniter 49 is arranged in the central recess 48 outside the canister container, and the transfer charge 50 is filled in the center of the canister container.

The transfer charge 50 is burned by the operation of the igniter 49, and the gas generant 47 is burned by this combustion to generate gas. This gas enters the coolant / filter chamber 45 through the opening 51, and the coolant 52 and the filter 5
It is cooled and purified while passing through 3, and flows into the airbag (not shown) through the discharge port 40.

[0004]

In the conventional gas generator described above, the diameter of the inner cylinder member 44 is large and the ceiling portion 54 thereof is large.
Since the span is long, the ceiling portion may be deformed due to the high pressure in the combustion chamber during gas generation. Deformation of the ceiling will have a negative effect on the gas flow.

In order to avoid interference with the gas generator mounting flange 55 when the opening 51 is drilled,
There is a problem that the position of the flange is restricted toward the igniter side of the gas generator. As a result, the amount of protrusion on the occupant side becomes large, which causes a problem in appearance.

Further, since there is no member for guiding and supporting the ignition means, it is difficult to integrally attach the igniter and the transfer charge or to attach the mechanical sensor.

Therefore, it is an object of the present invention to provide a novel gas generator that solves the above problems of the prior art.

[0008]

A gas generator for an air bag according to the present invention includes a housing having a gas discharge port, an ignition means and a gas generation means arranged in the housing, and the gas is generated by an impact. In the gas generator for an airbag, which introduces the gas generated by the generating means into the airbag to protect an occupant from an impact, the housing includes a first member and a second member, and the first member includes: A central tubular portion having one end closed and the other end open, an annular portion extending like a flange at the open end of the central tubular portion, and an outer tubular portion extending axially at the outer edge of the annular portion. The second member includes an annular portion having a central hole into which the central tubular portion can be fitted, and an inner tubular portion axially extending to the annular portion of the first member at an outer edge of the annular portion. , The central tubular portion,
An ignition means accommodating chamber for accommodating the ignition means is defined on the inner side, and a gas generating means accommodating chamber for accommodating the gas generating means is defined on the outer side together with the second member.

Further, it is preferable that the first member has a ring member surrounding the opening on the open end side of the central cylindrical portion, and a fixing member for fixing the ignition means is screwed to the ring member.

In the present gas generator, the annular portion (second member) having the central hole into which the central tubular portion can be fitted forms the ceiling of the gas generating means accommodating chamber (combustion chamber). Therefore, the span of the ceiling in the combustion chamber is shortened and the rigidity of the ceiling is increased. At the same time, the central tubular portion functions as a guide / support member for the ignition means.

Further, the first member and the second member which are separately formed
In the above member, by providing the second member with the combustion chamber opening for ejecting gas and the first member with the flange for mounting the gas generator, the combustion chamber opening and the flange can be provided at arbitrary positions. .

After arranging the ignition means in the central tubular portion, the ignition member is fixed in the central tubular portion by screwing the fixing member onto the ring member.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of an embodiment of the present gas generator. The gas generator includes a housing 2 having a gas outlet 1, and the housing 2 includes a first member 3, a second member 4 and a lid member 22.

The first member 3 is formed by press working, has a central tubular portion 5 having one end closed and the other end open, and an annular portion 6 extending like a flange at the open end of the central tubular portion 5. An outer cylinder portion 7 that extends axially to the substantially central position of the gas generator at the outer edge of the annular portion 6, and a mounting flange portion 8 that extends radially at the tip of the outer cylinder portion 7. And have. Also, the second member 4 is
Annular portion 1 having a central hole 9 into which the central tubular portion 5 can be fitted
0 and the first edge in the axial direction at the outer edge of the annular portion 10.
The member has an inner cylindrical portion 11 extending to the annular portion 6 and a flange portion 12 formed at the tip of the inner cylindrical portion 11 and abutting on the inner surface of the annular portion 6. The first member 3 and the second member 4 are joined to each other by circumferential welds 13 and 14.

The central tubular portion 5 has a squib (igniter) 1
An ignition means accommodating chamber 15 for accommodating an ignition means composed of 6 and an enhancer (transfer charge) 17 is defined inside. The ignition means is loaded from the open end of the central tubular portion 5 and is fixed by caulking a caulking portion 38 fixed around the open end. The central tubular portion 5 also defines a gas generating means accommodating chamber for accommodating the gas generating means on the outer side, that is, a combustion chamber 18 together with the second member 4. The gas generating means comprises a canister container 20 which is an annular thin-walled container made of aluminum and fitted in the central tubular portion 5.
Is filled with a disk-shaped gas generating agent 19.
Further, a wire mesh-shaped pre-filter 28 surrounding the gas generating agent 19 is disposed in the canister container 20, and the pre-filter 28 is adapted to collect the combustion residue generated by the combustion of the gas generating agent 19. . A coolant / filter chamber 21 is defined outside the combustion chamber 18 in cooperation with the lid member 22. The lid member 22 has an inner peripheral wall portion 23 and an outer peripheral wall portion 24, the inner peripheral wall portion 23 defines a central hole into which the inner cylindrical portion 11 is fitted, and the outer peripheral wall portion 24 is outside the first member. An outer peripheral wall of the housing is formed together with the tubular portion 7.
The coolant / filter chamber 21 is further defined by a retainer 25 into an upper chamber and a lower chamber, and a filter 26 as a purifying means is provided in the upper chamber and a coolant 27 as a cooling means is provided in the lower chamber. It is arranged.

An opening 30 for introducing the flame of the enhancer 17 into the combustion chamber 18 is provided between the ignition means accommodating chamber 15 and the combustion chamber 18, and the combustion chamber 18 and the coolant / filter chamber 2 are also provided.
1 is provided with ejection holes 29 for introducing the gas generated in the combustion chamber 18 into the coolant / filter chamber 19, and further, the coolant / filter is provided between the coolant / filter chamber 19 and the airbag (not shown). A plurality of gas outlets 1 for introducing the gas that has passed through the inside of the airbag are provided in the circumferential direction.

In the gas generator constructed as described above, when an electric signal is applied to the squib 16 due to impact and the squib 16 operates, the enhancer 17 ignites, and the high-pressure, high-temperature flame generated thereby ignites through the opening 30. The wall of the passage canister container 20 is broken and the gas generating agent 19 inside is ignited. The gas generated in the combustion chamber 18 is uniformly ejected from the ejection holes 29 and passes through the coolant 27 and the filter 26, during which the combustion gas is cooled and purified, and the cooled and purified gas is discharged from the exhaust port 1 through the air. It flows into a bag (not shown). This inflates the airbag and protects the occupant from impact.

In FIG. 2, the second member is the combustor cup 3.
An example constituted by 1 is shown. The combustor cup 31 includes an annular portion 33 joined to an inner surface of the lid member 35,
At the outer edge of the annular portion 33, there is an inner cylindrical portion 34 that extends axially to the step portion 6a formed in the annular portion 6 of the first member. The lid member 35 includes an annular portion 39 facing the annular portion 6 of the first member, and the annular portion 39 defines an inner peripheral wall portion 36 defining a central hole into which the inner tubular portion 5 fits on the inner peripheral side. And an outer peripheral wall portion 37 that forms an outer peripheral wall of the housing together with the outer cylindrical portion 7 of the first member on the outer peripheral side. A combustion chamber 18 is formed inside the combustor cup 31, and a coolant / filter chamber 19 is formed outside the combustor cup 31.

FIG. 3 shows another example of fixing means for fixing the ignition means. This fixing means includes a welded portion 62 on the first member.
The fixing ring 60 is fixed by the support ring 61 and the support ring 61 screwed to the fixing ring 60.
The fixing ring 60 is joined after pressing the first member, and surrounds the open port on the open end side of the central tubular portion 5. Further, the support ring 61 is an inward flange 63 that is locked to the ignition means and restricts the axial movement of the ignition means.
have. The ignition means includes a mechanical sensor 64, a detonator 66 that is carried by the detonator piece 65 in alignment with the firing pin of the mechanical sensor 64, and a transfer charge 67 that is ignited by the detonator 66.

When the ignition means is loaded, in the final step of the gas generator assembling process, the transfer charge 67, the detonator piece 65, and the mechanical sensor 64 are installed in this order from the open end side opening of the central tubular portion 5. Finally, the support ring 61 can be screwed and fixed to the fixing ring 60.

[0022]

According to the present invention, since the annular portion (second member) having the central hole into which the central tubular portion can be fitted forms the ceiling of the gas generating means accommodating chamber, the ceiling in the gas generating means accommodating chamber is increased. Has a shorter span, which increases the rigidity of the ceiling. As a result, at the time of gas generation, the problem that the ceiling is deformed due to the high pressure in the gas generating means accommodating chamber is eliminated.

Further, the first member and the second member which are separately formed
In the above member, the second member can be provided with a combustion chamber opening for ejecting gas, and the first member can be provided with a flange for attaching a gas generator, whereby a gas generator can be used for drilling the opening of the combustion chamber. It is possible to avoid a situation in which the mounting flange interferes with each other, and as a result, the combustion chamber opening and the flange can be provided at arbitrary positions.

Further, since the central tubular portion functions as a guide / support member for the ignition means, it becomes possible to integrally attach the igniter and the transfer charge, or to attach a mechanical sensor. In addition, an enhancer nozzle (opening 30) is provided in the central tubular portion.
Can be provided, which facilitates flame control of the gas generant, resulting in performance of the gas generator,
Operation stability is improved.

Furthermore, by the constitution of the ring member provided around the opening of the central tubular portion and the fixing member screwed to the ring member, the explosives can be charged in the final step of the gas generator assembly step and without using welding. Since the ignition means including it can be loaded, the safety at the time of assembling the gas generator is ensured.

[Brief description of drawings]

1 is a cross-sectional view of a gas generator according to the present invention.

FIG. 2 is a cross-sectional view showing another example of the gas generator according to the present invention.

FIG. 3 is a sectional view showing still another example of the gas generator according to the present invention.

FIG. 4 is a sectional view of a conventional gas generator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 discharge port 2 housing 3 1st member 4 2nd member 5 center cylinder part 6 annular part 7 outer cylinder part 10 annular part 11 inner cylinder part 15 ignition means accommodation chamber 16 squib (igniter) 17 enhancer (transfer charge) 18 Combustion chamber (gas generating means accommodating chamber) 20 Canister container (gas generating means)

Claims (2)

[Claims] 1. A shock including a housing having a gas discharge port, an ignition means and a gas generating means disposed in the housing, wherein gas generated by the gas generating means by impact is introduced into an airbag. In the gas generator for an airbag for protecting an occupant from the above, the housing includes a first member and a second member, and the first member has a central tubular portion with one end closed and the other end open, An annular portion that extends like a flange at the open end of the central tubular portion, and an outer tubular portion that extends axially at the outer edge of the annular portion, and the central tubular portion can be inserted into the second member. A ring-shaped portion having a central hole, and an inner tube portion that extends axially to the ring-shaped portion of the first member at the outer edge of the ring-shaped portion, and the center tube portion houses the ignition means inside. Ignition means housing chamber is defined and also outside Serial gas generator for an air bag, characterized by defining a gas generating device accommodating chamber for accommodating the gas generating means with said second member. 2. The first member has a ring member surrounding the opening on the open end side of the central tubular portion, and a fixing member for fixing the ignition means is screwed onto the ring member. Gas generator for airbags.